Lens edging machine



Oct. 13, 1931. A. E. MAYNARD 1,827,368

LENS EDGING MACHINE I Filed May '7, 1926 2 Sheets-Sheet 1 63 glwumtoz 62 (111w? fzfilaynard. 3% %lmu Oct. 13, 1931. A. E. MAYNARD 1,827,363

LENS EDGING MACHINE Filed May 7, 1926 2 Sheetls-Sheet 2 "I" 3140011101, a l? (llberf'fzmagnarcl W #7 SW Patented Oct. 13, 1931 UNITED STATESPATENT OFFICE ALBERT E. MAYNARD, OF SOUTHBRIDGE, MASSACHUSETTS, ASSIGNOR TO AMERICAN OPTICAL COMPANY, OF SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSOCIA- TION OF MASSACEUSETTS LENS EDGING MACHINE Application filed Kay 7, 1926. Serial No. 107,375.

vide means for tniing the face of such a grindstone after it has become worn.

Another objectis to construct such a machine provided with means for manually or automatically truing the peripheral face of a grinding stone of this nature.

A further object is to provide means whereby the former may be adjusted relative to the former shoe after the grindstone has been clamped against any axial displacement and the truing means has been positioned on the grindstone ready for the truing operation. 1

A still further object istoprovide means whereby the truing means may be reciprocated, and means whereby the reciprocatin means may be guided to form a V-shape face upon the grindstone,-which in turn is to be used in grinding a bevel on the edge of ophthalmic lenses.

A still further object is to provide such a machine which is strong and durable in its construction and effective in its operation.

Other objects and advantages of the invention should become apparent by reference to the following specification taken in connection with the accompanying drawings, and it will be understood that I may make any modifications in the specific arrangement of parts, details of construction and methods shown and described within the scope of the appended claim without departing from or exceeding the spirit of the invention.

In the drawings forming a part of this invention and wherein like characters of reference are used to designate corresponding parts throughout the several views:

Figure 1 is a diagrammatic plan view of a machine constructed in accordance with the present invention;

Figure 2 is an enlarged detail sectional view of the former adjusting means;

F1gure 3 is an enlarged detail sectional v1ew of the clamping means used in clamping the loosely mounted grindstone;

Figure 4 is an enlarged sectional view taken on line 44 of Figure 1 showing the automatic reciprocating means;

' F1gure 5 is a detail perspective view of a part of the former adjusting means shown in Figure 2;

Figure 6 shows the relative positions of the truing means and former with respect to the grlndstone and former shoe during the truing operation;

Figure 7 is a perspective view of the hone or trulng means;

Figure Sis a fragmentary side elevation of Figure 1 showlng the pivoted hone carriage and former shoe support.

When the grindstone 10 has been used for some time the groove 11 in the periphery thereof becomes somewhat worn and it is then essential that this groove be trued so.

that the proper edging of lenses may be achieved. Although the grindstonelO, displaceably connected as at 12 to the shaft 13,

is capable of axial displacement during the grinding or bevelling of lenses, it isessential when truing the stone that it be firmly held against movement. The grindstone 10 is an annular grindstone member which is connected to the grindstone shaft 13 by means of a flexible member 12. This flexible member 12 may be either a sheet of rubber, canvas or other fabric which is sufliciently rigid to hold the grindstone annulus 10 in its aligned position with respect to the shaft 13 and at the same time being flexible so that the grindstone 10 may be deflected or displaced axially with respect to the shaft 13.

To accomplish this object I provide the annular clamping members 14 and 15 mounted on the shaft 13 at either side of the grindstone 10 adapted for sliding movement toward and away from said stone. To achieve the sliding movement of the clamping members 14 and 15 the shaft 13 is formed with a longitudinal recess 16 extending from one end thereof inwardly to a point slightly beyond the grindstone and threaded within this recess 16 1s a plunger 17 having formed adjacent its inner end a circumferential groove 18 adapted to receive the reduced portions 19 of the screws 20 which are threaded in the clamping member 15 at diametrically opposite points. The said reduced portions operate in the slots 21- in the shaft 13 to permit sliding movement of the member 15. The plunger 17 has formed on its inner end the reduced threaded portion 22 threadedly received within the recess 23 of the rod 24.

Inserted through the clamping member 14 and the rod 24 is a securing pin 25 operating in the oppositely disposed slots 26 in the shaft 13 to permit the sliding movement of the clamp member 14. The fact that the pitch of the threads on the reduced portion 22 is twice that of the threads 27 on the plunger 17 will cause the clamping members to move at an equal rate of s eed toward or away from the grindstone w en the knurled portion 28 of the plunger 17 is rotated.

The shaft 13 is rotatably supported in the bearings 29 and is held against longitudinal movement by means of the collar 30 mounted on the shaft 13 by the tapered pin 31 or the like. Power is applied to the shaft 13 to rotate the grindstone 10 through the pulley 32 and belt 33.

A second pulley 34 mounted on the shaft 13 transmits power through the belt 35 to the pulley 36 mounted on the shaft 37 which is in turn supported within the bearings 38 carried by the base of the machine. Hingedly supported and reciprocally mounted on the shaft 37 is the lens carriage designated as a whole by the numeral 39. Mounted in the upper end of said carriage are the aligned lens clamping shafts 40 and 41 between which is adapted to be clamped the hone or truing means 42 to be rotated within the groove 11 of the grindstone. The lens carriage 39 is adapted to swing on the pivot 37 as shown in Figure 8 to move the hone 42 toward or away from the stone 10, the spring 73 being used to keep the hone in constant engagement with the stone.

Power is applied to rotate the hone or truing means through the gear 43 mounted on the outer end portion of the shaft 41 and the gear 44 mounted on the shaft 37 through the idler 45.

The reciprocating movement of the hone or truing means is created by the barrel cam 46 rigidly keyed to the shaft 37 which has a cam groove 47 formed therein adapted to receive the lower roller portion 48 'of the spring pressed plunger 49 mounted within the longitudinal bore 50 of the sleeve 51 which is in turn threadedly mounted within the lens carriage 39. The upper end portion of 65 said plunger is somewhat reduced as at 52 and carried by the reduced ortion is a transverse pin 53 inserted within the slot 54 in the sleeve 51, the reduced portion 52 extending outwardly of the sleeve and having fixed thereto an operating finger piece 55.

When it is desired to disengage the plunger from the barrel cam 46 it is only necessary to draw .it outwardly against the action of the spring 56 and slightly rotate the same so t at the pin 53 Wlll engage and rest onthe top wall 57 of said sleeve 51, thereby stopping the reciprocating motion of the lens carriage. A suitable former 58 is carried by the outer end of the shaft 41 to guide the honing or truing means 42, after said honing or truing means has been positioned within the groove 11, as illustrated in Figure 2. It is sometimes necessary to adjust the former 58 so it will be accurately positioned within the V 59 of the former shoe 60 carried by the base of the machine for it is essential that the distance between the center of the truing means 42 and the center of the former 58 be equal to the distance between the center of the groove 11 and the center of the V 59, this distance being variable during the grinding of different curved lenses so that means must be provided for adjusting the former along the shaft to compensate for the varying of the said distance. To accomplish this there is carried by the outer end portion of the lens clamping shaft 41 a bearing sleeve 61 having the laterall disposed annular flange 62 formed with the diametrically o posed lugs 63. Said lugs are adapted to e received within the recess 64 formed in the member 65 mounted on the reduced portion 66 of said shaft 41.

Themember 65 is threadedly received within the collar 67, which is held against the gear 43 by the aforementioned flange 62. The transverse pins 68 carried by the member 65 pass through the former 58 while threaded upon the reduced outer end 69 of the member 65 is a handle 70 which retains the former 58 in position on the pins 68.

To adjust the former relative to the former shoe the collar 67 is rotated and due to the threaded engagement therewith of the member 65 the latter will be caused to move in or out along said reduced portion 66 of the shaft 41, the lugs 63 engaging in the recesses 64 efl'ectively preventing the rotation of the member 65 as the collar 67 is rotated to draw it together with the former 58 to any desired position.

In operation the grindstone 10 is first clamped against any flexible or lateral movement in the-manner set forth above, after which a hone or truing wheel 42, such as shown in Figure 2 and Figure 7 is suitably held between the lens clamping shafts and positioned within the groove 11 of the grindstone. The periphery of the hone or truing no wheel is formed with the oppositely bevelled faces '71 and 72.

A suitable former 58 is then adjusted in the manner aforementioned to the V 59 in the former shoe which is of the angle desiredto be formed in the periphery of the grindstone 10. The spring pressed pin 49 is then positioned within the cam groove 47 and power is then applied to the machine. As the hone or truing wheel is rotated against the oppositely rotating grindstone the barrel cam 46 causes the carriage 39 along with the truing wheel 42 and former 58 to be reciprocated. The carriage 39 being pivoted at 37 allows the spring 73 to constantly urge the hone towards the grindstone 10 and through the cam action of, the V groove 59 to be 'simultaneousl moved towards and away from the grind stone during the reciprocation.

The path of the truing wheel 42 across the face of the grindstone 10 which is to be the former shoe is ad1 trued and which has the same V formed therein as the V 59 in the former shoe is guided by the former 58 operating within the V groove 59. The said former is ada ted of the grindstone, a slide having a threaded portion on said hone holding means, a former member mounted on the slide, a former shoe having a portion shaped to correspond with the shape edge of the grindstone and adapted to guide the movement of the hone over the face of the grindstone and a threaded collar on said hone holding means adapted to engage the threaded ortion of the slide and move said slide an former upon rotation of the collar to regulate the distance between said hone and former member so that said former member may be positioned in the former shoe to correspond with the position of the hone on the shaped edge of the grindstone.

' ALBERT E. MAYNARD.

to ride up and down the angled faces 0 the j 00% 59 during its reciprocating movement, whichsimultaneously causes the truing wheel 42 to likewise travel over the V groove 11 of the grindstone, thereby truing the same by removing a small portion of its face..

The amount that is to be removed from the grindstone is predetermined through the adjustment of the former shoe WlllCh is mounted on the slide 76. in the slide way 77 carried by the base 80 of the machine and which is'adjustable forwardly or rearwardly by rotating the screw 78 which is threadedly connected to the slide 76. To remove a the face of the grindstone greater amount of usted rearwardly, thereby allowing the trumg means to move further into" the grindstone prior to itsbeing held at a fixed position by the former 58 contacting with said former hoe. l

- The pin 49 may be disengaged from the and the hand lever 74 pivoted at may be used to move the truing wheel across the face of the stone if desire From the foregoing description it will be seen that I have provided simple, efiicient and inexpensive means for trumg the face of a grindstone of the character stated, and it will also be seenthat the truing 0peration is substantially automatic, the only operations necessary being the positioning of the v truing means and adjusting of the former.

Having described my invention, I claim:

A device of the lcharacter dlescribgd f0; use in honingt es ape inge geo a grindstone, means to hold the bone in en-. gagement with the grindstone, means to reciprocate the hone across the shaped edge 

